Switches with selection by co-ordinates

ABSTRACT

Crosspoint matrix for an electrical switch for selection by coordinates comprising a first set of conductive parallel bars located in a common plane and each carrying resilient forks and a second set of conductive parallel bars adapted to establish contact with said forks, this second set of bars being located in a plane spaced from the said common plane and parallel thereto. The bars of the second set have one conductive and one insulating surface against which the forks bear in make and idle positions respectively, with notches through the bars of the second set to allow the forks to pass through. The bars of the second set also have unnotched insulating bars intercalated between them to define with them receiving spaces comprised alternatively of two insulating surfaces and one insulating and one conducting surface.

United States Patent 335/112X ZOO/175 3,255,318 6/1966 McKee......................... 3387.108 6/1968 Reimer [72] inventors Pierre M. Lucas 20 rue Tariel, lssy-Les-Moulineaux; Auguste A. Sautel, 13 rue Anatole France, FOREIGN PATENTS 8/1964 Austria.........................

Primary Examiner-Robert K. Schaefer Bonneuil-sur-Marne; Serge M. Choupik, 1 rue des Fauvettes, 91 RisXJrangis, France 84 l ,5 18

21 AppLNo. 22 Filed Assistant Examiner-Robert A. Vanderhye AltorneyAbraham A. Saffitz July 14, 1969 45 Patented Feb.2,l97l

[32] Priority July 26,1968 [33] France through. The bars of the second set [56] References cued lating bars intercalated between them to define with them NI E STATES PATENTS receiving spaces comprised altemativel 3,233,050 2/1966 McKee 335/ 1 12X faces and one insulating and one conducting surface.

PATENTED rm 2|9n 3560.691

' sum 2 or a INVZNTORS:

Pierre M. LUCAS Auguste A. SAUTEL Serge M. CHOUP BYMW%/ I A'I'IO EY PATENTEUFEB 2|sn 3,560,691

SHEET 3 OF 4 INVENTOQE:

P re M. LUCAS, Augu e A. SAUTEL, Serge M. CHOUP K SWITCHES WITH SELECTION BY CO-ORDINATES This invention relates to matrices of crosspoints for selection by coordinates.

As is known, the crosspoints of the selection matrices of crossbar switches are commonly formed by sets of working contacts consisting of fixed metal blades ganged along one coordinate and of displaceable metal blades ganged along the other coordinate. These sets of contacts are actuated by means of flexible selection fingers allocated to each of the said contacts, by moving rectangular coordinate bars situated in parallel planes.

In application Ser. No. 755,259 filed Aug. 26, 1968, there is described a selection matrix which comprises:

a first set of conductive bars, which are parallel and equidistant, and situated in one and the same plane, each of these bars along its length bearing conductive and flexible selection fingers, at right angles to the plane of the bars and implanted along the axis of these;

a second set of conductive bars, which are parallel and equidistant, situated in one and the same plane parallel to the plane of the first set of bars, at right angles to these, each bar of this second set comprising incisions offering unobstructed passages for the selection fingers fastened on the bars of the first set.

The metal made available by cutting an incision is bent over transversely to the incised bar; a flap is thus obtained, forming a dihedron with the said bar, in which a given selection finger can be placed in position as a result of the longitudinal displacement imparted to the two sets of bars. The said finger, held in a bent position mechanically, thus ensures that the required contact is established at the scheduled crosspoint.

The object of the present invention is to provide another simplification in the multiplying of the contacts and greater reliability in operation of the contacts as such. According to the invention, the selection matrix comprises:

a first set of conductive bars, which are parallel and equidistant and situated in one and the same plane, each of these bars being formed by a flat metal blade of s appropriate thickness, in which appropriate outlines have been formed by excisions, in such manner that, by bending over, forks may be formed with two fingers which are equidistant and suitably resilient to establish satisfactory contacts by pressure;

a second set of bars, each consisting of a conductive bar backed by an insulating bar, these composite bars being situated in one and the same plane parallel to the plane of the first set of bars, at right angles to these; each composite bar comprises incisions or notches of rectangular outline, which are equidistant and formed in one of the edges of the said bar.

Adjacent to each composite bar and parallel to the same, is situated an insulating bar of the same dimensions, but not notched. The spacing between these different bars is established by means of insulating spacers of smaller width than that of the bars. Two types of alternate receiving sections are thus obtained between the different bars referred to in the foregoing; one of these types of receiving section comprises insulating surfaces only, whereas the other type comprises a conductive surface which faces towards an insulating surface.

The fingers of the forks integral with the first set of bars, can penetrate, as the case may be into one of the other of these receiving sections, owing to the incisions formed in the bars of the second set.

A connection is thus established at a point of intersection of two sets of bars, when the fingers or tines of a fork bear against the metal surface of a receiving section.

These connections are evidently established by imparting appropriate translatory displacements to the bars of the two sets. These displacements are such that at the instant of establishing a contact, each set of bars is actuated transiently and return immediately to its idle position. By contrast, upon Also it is possible for a very advanced degree of mechanical miniaturization to be achieved, whilst ensuring great reliability in respect of the quality of the contact.

The damping of the vibrations of the forks may be ensured by the structure of the selection matrix itself.

The invention will be further described with reference to the accompanying drawing, in which: g

FIG. 1 is an illustration in perspective of the appearance and arrangement of the coordinate bars of one form of selection matrix according to the invention;

FIGS. 2a, 2b and 2cillustrate excisions formed for the forks of a coordinate bar if the section matrix of the invention is a matrix comprising triple points of intersection;

FIG. 3 is an illustration in perspective of an embodiment of a crossbar switch according to the invention; and

FIGS. 4a to 4f show the consecutive stages of the engagement of a crosspoint.

The selection matrix of FIG. 1, described hereinafter by way of nonlimiting example, is a triple" matrix rendering it possible to establish three contacts at the same time at one and the same crosspoint.

An X coordinate bar 10 comprises three parallel and equidistant metal bars 11, 12, I3, encased in a block 14 of dielectric material. This block I4 has a form which will be described in detail hereinafter but which has been illustrated in parallelepipedal form in FIG. I.

The metal bar 11 carries bifurcated equidistant branches I 10 (FIG. 20). Each of these branches is situated in a plane at right angles to the bar and at side only of the plane of the bar. These branches 110 terminate in two fingers I1 I and I12.

The metal bar 12 carries equidistant bifurcated branches 120 (FIG. 2b). Each of the branches is situated in a plane at right angles to the bar and at either side of the bar. These branches 120 terminate in two fingers I21 and 122.

The metal bar 13 carries equidistant bifurcated branches 130 (FIG. 2c). ,Each of these branches is situated in plane at right angles to the bar and at one side only of the plane of the bar, this side being the other side compared to the case of FIG. 2a These branches 130 terminate in two fingers I3] and I32.

The branches are formed by bending; the different bends are needed tobe. able to perform the imbrication and alignment of the three forks I10, I20, 130 at one and the same point of intersection of the matrix of the invention at which three separate contacts are to be available.

Bifurcating with two fingers allows of better elasticity of the twinned contacts for a bending stress applied on the extremity of the fork and directed parallel to the arrow X.

FIG. 3 is an illustration in perspective of an embodiment of a crossbar switch according to the invention.

This Figure shows the X coordinate bar 10 whereof the dielectric block 14 (for example of polycarbonate), has the 7 following features.

One of the extremities terminates in an L-shaped part I5 carrying a peg 16 arranged to slide horizontally into an opening 17 of the frame 1 when the bar l0 is displaced horizontally. The other extremity (not shown in FIG. 3) terminates in a T-shaped part, each branch of the T having a peg arranged to slide in an opening of the frame. This method of fastening a bar 10 by means of three pegs, one being at one side and two at the other, renders it possible to prevent transversal oscillations of the bar whilst it is being displaced in the direction of the arrow X. The upper part of the bar I0 from which the forks 110, I20, 130 emerge, comprises teeth in such a manner that each fork is always situated between two teeth, for example, the fork is situation between the teeth 18 and I9.

The outline of these teeth is asymmetrical. The left flank (FIG. 3) is vertical and the base of each fork is substantially applied against this flank. The right-hand flank has a definite slope. As a result, flexing a fork such as 110 from the right towards the left requires a much smaller force than to flex the same fork from the left towards the right. As will be apparent hereinafter, these latter features will be exploited for easy release of the bars from one of their positions and to ensure the quality of the electrical contacts of the fingers of the forks which are established by pressure.

Referring back to FIG. 1, a Y coordinate bar 20 is formed by three metal blades 21, 22, 23, each backed by an insulating-blade, respectively marked 21, 22, 23' having the same dimensions as the metal blade to which it is joined to form therewith a composite blade. The lower edge of each composite blade 21-21, 22-22, 23-23 has cut in it notches 211, 212, in the'case of the pair2l-21', 221, 222. in the case of the pair 22-22, and 231, 232,. in the case of the pair 23-23'.

Each composite blade is coordinated with a long insulating intermediate blade, respectively marked 24, 25, 26, having the same dimensions as the composite blade but lacking notches. Short insulating separating or spacer elements 27, separate the combined blades and the intermediate blades. These spacers have a smaller height than the long intermediate blades, so that the Y coordinate bar contains passages or receiving sections such as 28 and 29. The fingers or tines of the forks 110, 120, 130 can be inserted into these receiving sections through the notches.

For example, the fingers 131 and 132 of the fork 130 can bar 20 to the idle condition by a reverse translatory motion, and FIG. 4e that following the return of the bar to the idle position. It is apparent from this FIG. 4e that an electrical contact is made between the two fingers 111-112 of the fork 110 and the metal blade 21, owing to the fact that this latter opposes the return of the fingers to their idle position. The contact pressure is provided by the elasticity of the fork 110 which then bears on the tooth 19 of the bar 10 (FIG. 3).

FIG. 4f illustrates the return to the idle position of the fingers 111-112 of the fork 110 by the releasing movement further thanks to the appropriate slope of the flank of the enter or leave the section-'28 between the dielectric blade 24 arrow Y, the notches 211, 212, 221, 222, 231, 232,

. will be situated respectively facing the fingers of the forks 110, 120, 130. A translatory displacement of the bar 10 in the direction of the arrow X, causes the fingers of the forks to penetrate into the sections in which one of the surfaces is of metal, i.e. into the operating position.

Accordingly, if the two bars 10, 20 then return to their initial positions, the fingers of the forks 110, 120, 130 will bear on the corresponding metal blades 21, 22, 23 and the three contacts required will be established at the same time at the desired point of intersection.

The release of these contacts is performed by the transient action of the bar 20, which, by a displacement identical to the preceding one, allows the contacts to regain their idle positions.

FIGS. 4a to 4f show the consecutive stages of the engagement of a cross-point of a selection matrix of the invention. In diagrammatical form, these figures illustrate the making and breaking of a single triple contact. These figures illustrate the part ol the bar 20 corresponding to the tworeceiving sections allocated-to the fingers of the fork 110 seen in -Lisa,w

" FIG. 4a shows the position of the fingers 111 and 112 of the fork 110 in its section 29 comprising insulating surfaces 21 and 25. In the idle position, these fingers bear on the blade 25.

FIG. 4b illustrates a translatory motion of the bar 20 which has the result of placing the notches 211, 212 in alignment with the fingers 111 and 112 of the fork 110.

FIG.- cshstwsas eceq a tr sl t r qt q of the bar 10 (not illustrated), which allows the fingers 111 and 112 of the fork 10 to penetrate into the receiving section 29 h mp i the meta aL aq 2 FIG. 4a illustrates the new situation after return of the tooth 18 (FIG. 3) of the bar.

It will be noted that the system of the invention is such that, for all the positions occupied by the fingers of the fork 110, the possible vibrations of these are damped, either by an insulating blade or 26, or by a conductive blade 21.

We claim:

1. A crosspoint matrix for an electrical switch for selection by coordinates comprising a first set of conductive parallel bars located in a common plane and each carrying resilient forks, a second set of conductive parallel bars adapted to establish contact with said forks, this second set of bars being located in a plane spaced from the said common plane and parallel thereto, and the bars thereof having one conductive and one insulating surface against which the forks bear in make and idle positions respectively, with notches through the bars of the second set to allow the forks to'pass through, the bars of the second set having unnotched insulating 1*: rs intercalated between them to define with them receiving spaces comprised alternatively of two insulating surfaces and one insulating and one conducting surface.

2. A crosspoint matrix as claimed in claim 1 in which the insulating bars are of the same overall dimensions as the bars of the second set.

3. A crosspoint matrix as claimed in claim 1 in which the notches in the pjll'S Qf the second set are of rectangular shape.

4. A crosspoint matrix as claimed in claim 1 in which the insulating bars are spaced from the bars of the second set by insulating spacers.

5. A crosspoint matrix for an electrical switch for selection by coordinates comprising a first set of conductive parallel composite bars located in a common plane, each formed by a plurality of conductive parallel individual bars,

each. having an extension bent at right angle to said individual bar and terminated in two fingers, the fingers of the extensions of the different individual bars forming a comand idle positions respectively, with notches through the bars of the second set to allow the fingers to pass through, the bars of the second set having unnotched insulating bars intercalated between them to define with them receiving spaces comprised alternatively of two insulating surfaces and one insulating and one conducting surface.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3 ,560 ,691 Dated February 2 1971 Inventor(s) Plerre M Lucas Gt a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Insert columns 3 and 4 as part of Letters Patent Signed and sealed this 9th day of April 1974 (SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner 0 Paten 

1. A crosspoint matrix for an electrical switch for selection by coordinates comprising a first set of conductive parallel bars located in a common plane and each carrying resilient forks, a second set of conductive parallel bars adapted to establish contact with said forks, this second set of bars being located in a plane spaced from the said common plane and parallel thereto, and the bars thereof having one conductive and one insulating surface against which the forks bear in make and idle post positions respectively, with notches through the bars of the second set to allow the forks to pass through, the bars of the second set having unnotched insulating bars intercalated between them to define with them receiving spaces comprised alternatively of two insulating surfaces and one insulating and one conducting surface.
 2. A crosspoint matrix as claimed in claim 1 in which the insulating bars are of the same overall dimensions as the bars of the second set.
 3. A crosspoint matrix as claimed in claIm 1 in which the notches in the bars of the second set are of rectangular shape.
 4. A crosspoint matrix as claimed in claim 1 in which the insulating bars are spaced from the bars of the second set by insulating spacers.
 5. A crosspoint matrix for an electrical switch for selection by coordinates comprising a first set of conductive parallel composite bars located in a common plane, each formed by a plurality of conductive parallel individual bars, each having an extension bent at right angle to said individual bar and terminated in two fingers, the fingers of the extensions of the different individual bars forming a composite bar being aligned parallel to said composite bar, a second set of conductive parallel bars adapted to establish contact with said fingers, the second set of bars being located in a plane spaced from the said common plane and parallel thereto, and the bars thereof having one conductive and one insulating surface against which the fingers bear in make and idle positions respectively, with notches through the bars of the second set to allow the fingers to pass through, the bars of the second set having unnotched insulating bars intercalated between them to define with them receiving spaces comprised alternatively of two insulating surfaces and one insulating and one c conducting surface. 